Air-cooled engine



A. C. SINCLAIR.

AIR CYOOLED ENGINE. APPLICATION FILED Aus.e.19|9.

Patented Jan. 25, 1921.

UNITED STATES PATENT OFFICE.

ALFRED CHARLES SINCLAIR, OF NEW ORLEANS, LOUISIANA, AS SIGNOR T0SINCLAIR v MOTOR 00., INC., OF NEW ORLEANS, LOUISIANA, A CORPORATION OFLOUISIANA.

AIR-COOLED ENGINE.

Specification of Letters Patent.

Patented Jan. 25, 1921.

To all whom it may concern:

Be it known that L'Anrnnn C. SINCLAIR, a citizen of the United States,residing at New Orleans, in the parish of Orleans and State ofLouisiana, have invented a new and useful Air-Cooled Engine, of whichthe following is a specification.

It is the object of my invention to cool internal combustion enginesefficiently by air, and especially by air which is also used forscavenging and internal cooling.

My present invention is especially intended to be used in the type ofengines set forth in my co-pending application Ser. No. 184,6 13, filedAugust 6, 1917 but in its broader aspects it is not limited to that typeof engine.

The accompanying drawings illustrate my invention: Figure 1 is avertical central section through one cylinder and crank-case section ofan internal combustion engine embodying my invention; and Fig. 2 is asection on the line 2-2 of Fig. 1. I

The engine may have any number of cylinders, of which only one is shownin the drawings. The cylinder is a cast-iron cylinder 10, providedexternally save at the points where the various ports and theirconnections are located with a circumferential series of longitudinalgrooves 11. Fitting tightly on this cylinder 10 is a jacket 12,preferably of aluminum because of its lightness and ease in machiningand. also because of its high heat conductivity. The aluminum jacket 12bears against the cylinder at the points between the grooves 11; butsuch grooves are air passages through which'cooling air travels ashereinafter explained, to cool the cylinder 10. The jacket 12 isprovided with circumferential flanges 13, for radiating the heat whichthe jacket receives from the cylinder 11. Thus the cylinder is cooledboth by the heat radiation from the flanges 12 and also by theabsorption of heat by the air which passes through the grooves 11.

At the top of the cylinder. 10 is a valve seat member 15, which isalso'surrounded by the jacket 12. This valve-seat member is provided'with an intake space 16,.wh1ch receives the explosive mixture from anysuitable source, and'with an exhaust space 17, which receives the gasforced out of the engine cylinder on the up-stroke of the associatedpiston 18. The gas forced out of the cylinder at this time is almostwholly air, because of the scavenging action which will be explainedlater; and this air cools the walls of the cylinder 10 effectively fromthe inside. The exhaust space 17 is connected, by suitable grooves 19 onthe inside of the acket 12, with the upper ends of the grooves 11 in theexterior of the cylinder 10,

so that the air which is discharged into the exhaust space 17 is carrieddown through the grooves 19 and 11. The grooves 11 are separate in theupper and lower parts of the cylinder. The lower ends of those in theupper part lead into a circumferential passageway 20 formed in thejacket 12, which continuous circulation of air through such lowergrooves, the air entering through the openings 23, being heated in andpassing through the lower grooves 11 and cooling the cylinder in itspassage, and escaping through the atmosphere through the opening 22.

The valve-seat member 15 is provided with suitable ports communicatingwith the intake space 16 and exhaust space 17. With this valve-seatmember cooperates an oscillating valve 25, which is provided with ports26 which by the oscillation of such valve in any suitable manner may bemoved into registry with the ports from the intake space 16 during theintake period of the engine, and into registry'with the ports leading tothe exhaust space 17 during the ex haust period of the engine, and outof registry with both sets of ports during the compression and explosionperiods. The cylinder 10 is provided in its side walls with one or moresupplemental exhaust ports 27 which communicate with the exhaust opening21 and are uncovered by the piston 18 at the lower end of the pistonstroke, to allow the burned gases from the explosion to escape from thecylinder when such ports are uncovered. The cylinder 10 is alsoprovidedi on the opposite side from the supplementa exhaust ports 27,with one or more scavenging air-inlet ports 28, for admitting scavengingair into the cylinder shortly after the supplemental exhaust ports 27are first uncovered by the piston. The scavenging air thus admittedthrough the ports 28 sweeps out from the inside of the cylinder the bulkof the burned gases which are in the cylinder at the end of theexplosion period, so that such burned gases are replaced by the freshscavenging air; and when the piston 18 moves upward on its exhauststroke it is thus practically nothing but this displacing scavenging airwhich is forced out through the ports 26 and into the exhaust space 17and therefrom through the grooves 11 between the cylinder 10 and itsjacket 12.

The scavenging air supplied through the ports 28 is obtained bycrankcase compression, preferably in the manner set forth in myaforesaid co-pending application. A rotating valve 30 is suitablyoperated to admit air into the crank-case section 31 whenever the pistonmoves upward, on its compression and exhaust strokes, and to allowsuch'air to pass from the crank-case section 31 to the ports 28 of thecylinder 10, or of an associated cylinder in which the piston is movingcorrespondingly but at the exactly opposite'point from the c cle, whenthe piston'is moving downwar on its explosion and intake strokes. Thi isfully explained in my aforesaid co-pending application. When the piston18 uncovers the ports 28 at the end of its explosion stroke, the airfrom the crank-case section 31 as well as the air from the crank-casesection of the cylinder which is at the diametrically opposite point inthe cycle is admltted through the valve 30 and such scavenging air ports28 into the cylinder 10, to sweep'out the burned gases through thesupplemental exhaust ports 27 and displace such burned gases with freshair.- This fresh air, as stated, cools the cylinder walls 10 from theinside during the exhaust stroke of the piston, and when itis forced outthrough the ports 26 it passes into the exhaust space 17 of thevalve-seat member and thence through the grooves 12 in parallel to cool.the cylinder walls from the outside.

The valves 25 and 30 are operated 1n any suitable manner. As shown, thevalve 30 is driven by suitable gearing from the crank shaft 32 at halfthe speed of rotation of the crank shaft, so that it makes one rotationfor each engine cycle; the crank shaft 32 is connected to the piston 18by the usual connecting rod 33. The valve 25 is operated,

Lesa-rev as for instance by the mechanism set forth in my aforesaidco-pending application, so that it is stationary during the compressionand explosion periods of the engine and then has its ports 26 out ofregistry with both the intake and exhaust ports of the valve-seatmember, and so that it is moved only during the intake and exhaustperiods, during which periods it is not under pressure from within thecylinder.

I claim as my invention:

1. In an internal combustion engine, a cylinder, a metal jacketfittingon said cylinder, the abutting surface of one of said parts whereit fits against the other being provided with longitudinal grooves, andconnections to said grooves for causing a circulation of air throughthem in parallel and through the cylinder in series with the grooves,said jacket being provided with heat-radiating flanges.

2. In an internal combustion engine, a cylinder having intake andexhaust ports, and a metal jacket fitting on said cylinder, the abuttingsurface of one of said parts where it fits against the other beingprovided with longitudinal grooves, said grooves having openings to theatmosphere at points of different heights and separated from thecylinder exhaust port so that by the heating effect of the cylinder onthe air in such grooves there is a natural circulation of air throu hthe grooves.

3. l ii an internal combustion engine, a cylinder, a metal acket fittingon said cylinder, the abutting surface of one of said parts where itfits against the other bein provided with longitudinal grooves, anconnections to said grooves for causing a circulation of air throughthem in paralleland through the cylinder in series with the grooves.

4. In an internal combustion engine, a cylinder, a metal jacket fittingon said cylinder, the abutting surface of one of said parts where itfits against the other being provided with grooves, means associatedwith said cylinder for displacing by scavenging air the burned gases inthe cylinder at the end of the explosion period, and a valved port bywhich said scavenging air when forced out of said cylinder is conductedthrough said rooves.

5. ii an internal combustion engine, a cylinder and a piston, saidcylinder being provided with a plurality of circumferentially spacedlongitudinal passageways in its walls, and means for causing acirculation of air through said passageways in parallel and through thecylinder in series with the grooves.

6. In an internal combustion engine, a cylinder and'a piston, saidcylinder being provided with a plurality of circumferentially spacedlongitudinal passageways in its walls, and means for causing acirculation of air through said passageways in parallel and through thecylinder.

7. In an internal combustion engine, a cylinder and a piston, saidcylinder being provided with a plurality of circumferentially spacedlongitudinal passageways in its walls means associated with saidcylinder for displacing by scavenging air the burned gases in thecylinder at the end of the explosion period, and a valved port by whichsuch scavenging air when forced out of said cylinder is conductedthrough said passageways in parallel.

8. .In air-internal combustion engine, a cylinder and piston, saidcylinder being provided with main intake and exhaust ports which areopen during the intake and exhaust periods of the engine and withsupplemental exhaust and scavenging-air inlet ports which are opened tosweep out by scavenging air the burned gases in the cylinder at the endof the explosion period, said cylinder walls being provided with aplurality of circumferentially spaced longitudinal passageways which areconnected with the main exhaust port when it is open so that the gasesdischarged from the cylinder during the exhaust period are forcedthrough such passageways in parallel.

9. In an internal combustion engine, a cylinder and piston, saidcylinder being provided with main intake and exhaust ports which areopen during the intake and ex haust periods of the engine and withsupplemental exhaust and scavenging-air inlet ports which are opened tosweep out by scavenging air the burned gases in the cylinder at the endof the explosion period, said cylinder being provided with longitudinalexternal grooves, and a metal jacket fitting over said cylinder andmaking longitudinal passageways of said external grooves, and saidpassageways being provided with, connections to the main exhaust portso. that when said main exhaust port is open the gases expelled from thecylinder are forced through said passageways.

10. In an internal combustion engine, a cylinder and piston, saidcylinder beingprovided with main intake and exhaust ports which are openduring the intake and exhaust periods of the engine and withsupplemental exhaust and scavenging-air inlet ports which are opened tosweep out by scavenging air the burned gases in the cylinder at the endof the explosion period, said cylinder'being provided with longitudinalexternal grooves, and a metal jacket fitting over said cylinder andmaking longitudinal passageways of said external grooves, and

said passageways being provided with connect-ions to the main exhaustport so that when said main exhaust ort is open the gases expelled fromthe cy inder are foroed through said passageways, said jacket being ofhigh-heat-conductivity metal and being provided with externalheat-radiating flanges.

11. In an internal combustion engine, a cylinder and piston, saidcylinder being provided with main intake and exhaust ports which areopen during the intake and exhaust periods of the engine and withsupplemental exhaust and scavenging-air inlet ports which are opened tosweep out by scavenging air the burned gases in the cylinder at the endof the explosion period, said cylinder being provided with longitudi'nal external grooves, and a metal jacket fitting over said cylinder andmaking longitudinal passageways of said external grooves, and saidpassageways being provided with connections to the main exhaust port sothat when said main exhaust port is open the gases expelled from thecylinder are forced through said passageways, said jacket being .ofhigh-heart-conductivity metal.

12. In an internal combustion engine, a

cylinder and piston, said cylinder being provided with main intake andexhaust. ports which are open during the intake and exhaust periods ofthe engine and with supplemental exhaust and scavenging-air inlet portswhich are opened to sweep out by scavenging air the burned gases in thecylinder at the end of the explosion period, said cylinder beingprovided with longitudinal external grooves, and a metal jacket fittingover said cylinder and making longitudinal passageways of said externalgrooves, and said passageways being provided with connections to themain exhaust port so that when said main exhaust port is open the gasesexpelled from the cylinder are forced through said passageways, saidjacket being provided with external heatradiating'fianges. r

13. In an internal combustion engine, a cylinder and piston; saidcylinder being provided with main intake and exhaust ports which areopen during the intake and exhaust periods of the engine and withsupplemental exhaust and scavenging-air inlet ports which are opened tosweep out b scavenging air the burned gases in the cy inder at the endof the explosion period, said cylinder walls being provided with aplurality of circumierentially spaced longitudinal passageways which areconnected with the main exhaust port when. it is open so that the gasesdischarged from the cylinder during the exhaust period are forcedthrough such passageways in parallel, said supplemental exhaust andscavenging-air in let ports being located in the cylinder walls so thatthey are covered and uncovered by the piston movement and are uncoveredat the end of the explosion period.

14:. In an internal combustion engine, a

cylinder and piston, said cylinder being provided with main intake andexhaust ports which are open during the intake and exhaust periods ofthe engine and with supplemental exhaust and scavenging-air inlet portswhich are opened to sweep out by scavenging air the burned gases in thecyl inder at the end of the explosion period, said cylinder beingprovided with longitudinal external grooves, and a metal acket fittingover said cylinder and making longitudinal passageways of said externalgrooves, and said passageways being provided with connections to themain exhaust port so that when said main exhaust port is open the gasesexpelled from the cylinder are forced through said passageways, saidsupplemental exhaust and scavenging-air inlet ports being located in thecylinder walls I so that they are covered and uncovered by the pistonmovement and are uncovered at the end of the explosion period,

15. In an internal combustion engine, a cylinder and a piston, saidcylinder being provided with a plurality of spaced passageways in itswalls, and means associated with said cylinder for displacing byscavenging air the burned gases in the cylinder at the end of theexplosion period, said passageways being so connected with the cylinderthat when scavenging air is forced out of the cylinder it passes throughsuch passageways in parallel. 1

In witness whereof I have hereunto set my hand at New Orleans,Louisiana, this first day of August, A. D. one thousand nine hundred andnineteen.

ALFRED CHARLES SINCLAIR.

